plenum trumpets

[chris390]

i just just the top off the plenum to investigate a light rattle on the top end and having seen photo on here of somebody elses loose trumpets and guess what - 2 rattling round. one seems to push back in fairly tight and i was going to use loctite but the other is very loose when refited so the question is does anybody have any good ideas about filler , resins or whatever to stick it back in ? thanks.

[blaineuk]

instant gasket should be ok

[wedg1e]

Even if they seem tight when cold they often loosen once warm: that's how I get them out to mill the bases down - stick the whole thing in the oven

Try instant gasket; I dunno what the original was, probably some Loctite anaerobic sealant.

[350matt]

A worthwhile mod while your're there is to shorten them all by about 25mm, as this will give a bit more poke and give the trumpet less leverage to walk out again, plus you'll be gluing in a clean bit of pipe as opposed to the portion which has been walking in and out of the bore for the last few thousand miles.

Matt

[trackcar]

Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out

[wedg1e]

trackcar said:

Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out

Another job for the weekend then

[rev-erend]

trackcar said:

Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out

Funny - I remember everyone (not necessarily Jules) slagging off the Takara for having this ..perhaps TVR Power know their stuff after all

[TOPTON]

350matt said:

A worthwhile mod while your're there is to shorten them all by about 25mm, as this will give a bit more poke and give the trumpet less leverage to walk out again, plus you'll be gluing in a clean bit of pipe as opposed to the portion which has been walking in and out of the bore for the last few thousand miles. Matt

Is it really that simple, does it not affect the running in any way?
If it is then I will have a fiddle over the weekend

[chris390]

thanks everybody , i like the sound of matts idea to get some non worn tumpet location , i think this may slightlly alter the low rev torque characteristics but not realy enough to notice.

[dickymint]

Another method would be to use a centre punch a few times around the base to give a slightly increased diameter. Then tap the trumpets back in.

[ACT]

rev-erend said:

trackcar said: Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out Funny - I remember everyone (not necessarily Jules) slagging off the Takara for having this ..perhaps TVR Power know their stuff after all

Having no trumpet in the base at all will offer the highest peak bhp figure, but there will be a loss in the midrange, its horses for courses, TVR Taraka is designed for bhp and value, TVR Power do know what they are doing, and i have done some development work with them on their demo car, they also offer trumpets as an extra.
Personally i wouldn't run without trumpets, shortening them will help the top end breath a bit better.

[number 7]

rev-erend said:

perhaps TVR Power know their stuff after all

I'm sure they have an imense amount of experience and expertise, but I still can't get my head around the straight tubes that the 500's came with, when everyone else seems to think that a flared end (even if it's just the trumpet base itself) is the way to go.

7.

[dickymint]

ACT said:

rev-erend said: trackcar said: Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out Funny - I remember everyone (not necessarily Jules) slagging off the Takara for having this ..perhaps TVR Power know their stuff after all Having no trumpet in the base at all will offer the highest peak bhp figure, but there will be a loss in the midrange, its horses for courses, TVR Taraka is designed for bhp and value, TVR Power do know what they are doing, and i have done some development work with them on their demo car, they also offer trumpets as an extra. Personally i wouldn't run without trumpets, shortening them will help the top end breath a bit better.

Nice to hear from you Tim
You still ok for BBWF?

[trackcar]

number 7 said:

rev-erend said: perhaps TVR Power know their stuff after all I'm sure they have an imense amount of experience and expertise, but I still can't get my head around the straight tubes that the 500's came with, when everyone else seems to think that a flared end (even if it's just the trumpet base itself) is the way to go. 7.

there's nothing wrong with the 500 tubes until very high hp figures .. they aren't straight, they have a gradual taper to them which looks straight at first glance. I did some back to back testing on a griff with std 500 tubes versus trumpets and gained only 2bhp with the trumpets, it was at the end of some development work and it had gone from 260odd bhp to 280 and i wanted to get more so tried flared trumpets .. went from 280 to 282bhp.

[trackcar]

rev-erend said:

trackcar said: Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out Funny - I remember everyone (not necessarily Jules) slagging off the Takara for having this ..perhaps TVR Power know their stuff after all

I too dismissed the blended trumpet base initially based on what had been the accepted norm until that point .. I unreservedly take it all back (in fact I did do shortly after anyway) as the blended base works incredibly well and all it takes is an hour with a cutter in a drill

[FrenchTVR]

Joo, have you got any pics showing what the blended base looks like?

[number 7]

trackcar said:

there's nothing wrong with the 500 tubes until very high hp figures .. they aren't straight, they have a gradual taper to them which looks straight at first glance. I did some back to back testing on a griff with std 500 tubes versus trumpets and gained only 2bhp with the trumpets, it was at the end of some development work and it had gone from 260odd bhp to 280 and i wanted to get more so tried flared trumpets .. went from 280 to 282bhp.

I wasn't aware they had a taper - learnt something today. However, my point was more to do with the flare (or lack of) which I perhaps mistakenly had attributed to the necessity to notch the mouths to get them to all fit, and the extra work and time that this would require. Your gain of 2BHP was presumably peak, can you recall what the midrange comparisons were?

7.

7.

[deetes]

trackcar said:

rev-erend said: trackcar said: Or take them all out and blend a radius into the trumpet base which everyone said would be a killer on my car but it's making the highest hp it's ever done since i bought it .. not as quick or easy as Matt350's suggestion though which is 10 minutes with a saw once you get the pipes out Funny - I remember everyone (not necessarily Jules) slagging off the Takara for having this ..perhaps TVR Power know their stuff after all I too dismissed the blended trumpet base initially based on what had been the accepted norm until that point .. I unreservedly take it all back (in fact I did do shortly after anyway) as the blended base works incredibly well and all it takes is an hour with a cutter in a drill

Yeah I'd like some pics of that as well, if possible.

[trackcar]

I'll have to take the plenum off again then, will do over weekend and post then

[FrenchTVR]

Top man